Results of spectrum analysis using method a (cf. Sect. 3.3, Table 2), shown for the H_δ -H_γ region (left) and the region around the Mg I b triplet (right). First row: observed, continuum adjusted composite spectrum (black), best-fitting synthetic spectrum (red), and shifted difference spectrum (green). The inverse of the applied continuum correction is shown in blue. Second row: same for the secondary. Third row:flux ratio of the secondary to primary from photometry (black) from spectrum analysis based on R₂ ∕R₁ = 0.926 (red) and assuming the adjusted ratio of 0.78 (green).